1. Field of the Invention
This invention relates generally to portable blowers and power modules, and, more particularly to an electrically driven backpack device that may also be used with various tools taking power from the backpack.
2. Description of Related Art
The following art defines the present state of this field:
Casper et. al. U.S. 4,989,323 describes a portable power unit for use with various power tools.
U.S. Pat. No. 4,451,983 discloses a flexible drive shaft with a drove head that fits into a drive socket. A shroud is turned to align a set screw with the threaded opening to attach the coupling. A power handle assembly is attached to a flexible drive shaft. The flexible drive shaft powers a rotary tool. A tubular liner covers the flexible drive shaft.
U.S. Pat. No. 2,790,292 discloses a rigid shaft with a key and a set screw for attachment to an elbow coupling. The combination has a motor with an output shaft. There is a right angle drive mechanism that transmits rotatable power to a flexible drive shaft. A hand grip is connected to the flexible drive shaft. Portable hand tools can be connected to the flexible shaft.
U.S. Pat. No. 4,341,017 discloses a guide bar mounted on the end of a handle provided with a throttle trigger. A harness carries a drive unit which conducts oil to lines which run through the guide bar to a hydraulic motor which runs a sprocket wheel to drive a saw.
U.S. Pat. No. 4,483,070 discloses a trimmer cutting head mounted on a rod which extends from a pistol grip control handle with a second handle midway on the rod for control. The trimmer cutting head is suspended from a cord that is mounted on a backpack extension. The backpack carries a gasoline engine powered alternator connected to a pair of mount brackets secured to the backpack. The pistol grip handle has a trigger switch that is in circuit with a cutting head motor. The cutting head motor is attached to the trimmer cutting head.
U.S. Pat. No. 3,540,123 discloses a frame to be carried on the back of an operator. The frame has upper and lower mounting plates, a mounting pivot and straps. A control lever is also attached to the frame. A coupling connects the engine to a flexible cable. There are flexible tube portions surrounded by rubber like plastic coverings. A rigid central pipe section is fitted in between the flexible tube sections and has handles. The flexible tube is threaded to a housing that in turn is threaded to a bearing housing. A collar is secured to the housing by clamp screws. The flexible cable has a male end that fits into a square cross section of a sleeve coupling member.
U.S. Pat. No. 4,242,855 discloses a lawn mower engine with an adapter for clipping to a flexible cable mounted within a housing. The flexible cable has an extension for slipping into a rotatable drive. The driver has a square end for fitting into a socket on the end of a second flexible cable within a trimmer. The driver is positioned within the end of the handle of the trimmer.
U.S. Pat. No. 4,098,292 discloses a quick disconnect coupling for detachable connecting a pair of fluid conveying conduits. The coupling 20 is comprised of a female body member 21 and a second tubular or male body member 22. Surrounding the female body member 21 is a locking collar 42 for movement so that when in locking position it forces the restraining balls 44 into an annular recess 31 to interconnect the male body member 22 with the female body member 21.
U.S. Pat. No. 4,541,160 discloses a rotatable flexible shaft for coupling one of several driving members to one of several driven members. The flexible shaft is adaptable as a coupling for any one of many driving members to any one of many driven members wherein the members may have output and input shafts, respectively, of varying sizes. Different adapters may be used to provide the coupling to the different size shafts.
U.S. Pat. No. 4,653,254 discloses a motor-driven lawn and garden device that provides the power source for lawn and garden equipment. The lawn equipment may be a trimmer that is connected by a flexible drive shaft and connected to the trimmer shaft. The patent discloses the connection of the drive shaft to the power driven drive shaft 16 of the lawn mower.
U.S. Pat. No. 4,213,482 discloses a detachable hydraulic coupler that includes a male and female portion. The section of the female portion enclosing the male portion includes a series of locking balls slidable in apertures that extend into a groove in the male portion to lock the coupler portions together. A slidable collar encircling the female portion normally holds the locking balls in locking position.
U.S. Pat. No. 3,611,748 discloses a male ended quick convert flexible drive shaft structure that is particularly adapted for use with an electronic equipment repair and maintenance unit. The male end assembly 70 has two grooves 80 and 90 spaced apart a distance such that when the spring loaded ball 35 is in groove 90 the flexible drive shaft is connected to the motor. On the other hand, while the motor 12 is still running, the flexible drive shaft can be placed in a non-operating drive while the male member is still fixed to the motor housing panel by having the spring loaded ball 35 in the groove 80.
U.S. Pat. No. 4,057,114 discloses a flexible shaft connected directly to the crank shaft of a snowmobile engine by a coupler. The flexible shaft is used to drive an ice auger bit. Attached to the flexible shaft is a reduction gear that rotates the drive shaft of the ice auger bit at a substantially reduced speed.
U.S. Pat. No. 3,505,831 discloses a flexible shaft coupler. The flexible shaft coupler disclosed eliminates the use of bearings of any type.
U.S. Pat. No. 4,664,420 discloses a female pneumatic coupling that releasably engages a groove nipple attached to a pneumatic tool. The locking sleeve has a series of combination locking tumblers which must be rotated to a preselected number so that the locking sleeve may be moved to deactivate the ball bearing latch. Removal of the tool attached to the groove nipple is prevented therefore unless the persons knows the combination of the selected numbers of the locking tumblers.
The prior art teaches various portable power units, one of which can be enclosed in a backpack and powered by either gasoline or electricity. However, the prior art does not teach a portable power unit which is powered by either electrical current or rechargeable batteries and which also has a sound absorbing layer lining the backpack enclosure, thereby reducing operational noise. The present unit is designed for powering a wide range of garden and other utility services tools from the portable backpack. The present invention fulfills these needs and provides further related advantages as described in the following summary.